Looking back at my question I think I was not very clear. To reproduce my issue, create a new table, then drag it to a new arbitrary width. Suppose the width appears in the Format/Arrange/Width field as 275 points. Now type 275 into the same field. The width of the table will slightly change, indicating that there are extra hidden digits in the width field.
The same thing happens if to column or row widths if you create a table and resize it. The column width might read, say, 92 pt after resizing the entire table, but upon typing in "92" into the width field the column will slightly change.
So I think that when you type in a number it is rounded to the nearest point, but when you drag a table, row, or column there are extra hidden digits.
The relevance of all of this is that I am trying to make a large spreadsheet that is made of a number of individual tables that I would like to be nicely aligned. They sometimes don't quite line up, even though looking at their various width/height fields they should. I can fix the issue by re-typing the field values, which evidently rounds them to integer values. But there is no way to see which fields are at fault, because the extra digits are not shown.